Time delay circuit



April 30, 1935. E, H, HOLT 1,999,811

TIME DELAY CIRCUIT Filed Sept. 5, 1931 PELEAJE 53 F1 age ItTLTEHIF EinarH. Halfari- Patented Apr. 30, 1935 uoaau 'rmn lanar omcvrr Einar B.Holt, Chicago, 11]., animal, by memo assignments, to Associated ElectricLaboratcries, Inc, Chicago, 11L, a corporation of Delaware ApplicationSeptember a, 10:1 Serial No. 561,017 4 omm/ (01. 171411) The presentinvention relates to'a time delay circuit arrangement which has for itsfunction the performance 01' a certain duty when a speciflc event takesplace for a given interval of 5 time and to continue said performancefor a definite period time after the termination of said event.

The circuit arrangement or this invention has been shown in itspreferred embodiment in association with a current distributing circuit,or line, and has for its-function the giving 01' an alarm signal toindicate a cessation of the current flow in that line when the currentstops flowing for aoperiod of at least one-tenth oi a second, and themaintaining or that signal for a period of three seconds after thecurrent flow has been restored.

In the associated drawing, in which the invention is diagrammaticallydepicted by con- 20 ventional symbols, the current distributing line isdesignated by the reference character L. Bridged across the twoconductors of line L is the relay I which is energized when currentflows in line L and which is deenergized when there is no currentflowing therein. This relay I has been shown in its energized position,indicating that current is flowing in the line.

When there is a failure in the current flow in line L, relay Ideenergizes and retracts its armature, thereby at the resting contact oithe armature, completing the obvious circuit of slow-torelease relay- 2.Relay 2 thereupon operates and at its armature and make contactcompletesthe obvious circuit 01 slow-to-operate relay 3.

Reay I energizes when its circuit is closed and attracts its armatures 4to I, inclusive, at its armature 4 connecting conductor 1 to groundthereby completing the circuit of relay ll by way of normally engagingcontacts I or dashpot relay I, at its'armature 5 connecting conductor 8to ground, thereby completing the circuit oi slow-to-release relay 9 byway of normally engaging contacts I! oi! dash-pot relay l4, and at itsarmature 0, opening a point in the circuit 01 dash-pot relay ll.

Relays 9 and .II operate when their circuits are closed by relay 3.Relay 9, upon operating, at its armatures I0 and It makes multipleground connections to conductors 1 and 8 to hold itself 0 and relay l3energized independently of relay 3, while at its armature l2, relay Icloses a point in the circuit-of dash-pot relay ll. Relay II,

upon operating, closes the circuit of the device B, which may be anysuitable type 01' signal ing, 5 recording, or registering device, togive an indiconnections supplied through armatures H and Ill,respectively, of relay 9. Relay 3 in retracting its armature 6.completes the circuit of dash- 'pot relay H by way of armature l2 andmake contact of relay 9.

Dash-pot relay ll slowly elevates its plunger in the well-known manner.The plunger of relay I4 is so adjusted that three seconds is requiredfor the plunger to be elevated enough to separate contact sets II andI6. However, when this occurs, the circuits oi relays 9 and I3 areopened, whereupon those relays deenergi'ze, relay 9 at its armature 42opening the circuit of dash-pot relay H, and relay ll opening thecircuit of the device B.

' Should there be another failure of the current flow before theplunger'ot relay I4 has separated a the contacts of the sets 15' and I6,relay 3 will open the circuit of dash-pot relay l4 and the plunger ofthat relay will restore without opening the circuits of relays 9 and II.Thus the circuit of the device B will remain closed.

, Relay! is so adjusted that at least one-tenth of a second elapses'after the deenergization oi relay I before it operates sufllciently toclose the circuits oi relays I and i3.

From the foregoing it will be appreciated that the arrangement of thisinvention provides timing means which causes a signal to be given whilean event is taking place, but only when such event has taken place foradeflnite length of time, and which causes said signal to be maintainedfor a definite period of time after the-termination of the event.

The invention having been thus described, what is considered new and isdesired to have protectedby Letters Patent is pointed out in the claimswhich follow. v

What is claimed is:

1. In combination with a current distributing circuit, a signallingcircuit, a relay connected in the'distributing circuit energized whilea'potential is present in the distributing circuit anddeenergizedwhenever a failure of said potential 1 occurs, means forclosing said signalling circuit, timing means operated by said relayeach time it deenergizes for operating the first mentioned means toclose said signalling circuit whenever said relay remains deenergizedfor a given period of time, means operated by said timing means formaintaining said first means operated to maintain said signallingcircuit closed, and other timing means operated by said first timemeans, when said relay reenergizes, to restore said first means and saidmaintaining means after a predetermined delay to thereby open saidsignalling circuit.

2. A time delay arrangement comprising a line circuit, a relay connectedin the line circuit and energized and deenergized by the presence orabsence of potential existing thereon, a second circuit, a second relaytpr closing said second circuit, timing means operated by said firstrelay when it deenergizes and maintained operated as long as said firstrelay remains deenergized, said timing means, upon operating, operatingsaid second relay to close said second circuit whenever said first relayremains deenergized for .a given period of time, means operated by saidtiming means for maintaining said second relay operated to maintain saidsecond circuit closed, and other timing means operated by the firsttiming means when said first relay re-energizes to restore said secondrelay to thereby open said second circuit a given period of time aftersaid reenergization.

3. In a current distributing system, a current distributing circuit, arelay in said circuit energized as long as a potential is maintained insaid circuit, said relay deenergized whenever a tailure in saidpotential occurs, a signalling circuit, means operating as a result of adeenergization of said relay oi a given duration for closing saidsignalling circuit, saidmeans remaining operated throughout the duration0! said deenergimtion to maintain said signalling circuit closed, meansoperating as a result of. the operation of said first means formaintaining said signalling circuit closed upon the restorationoi saidfirst means following the reenergisation of said'relay, and timing meansoperating as theruult of the restoration of said first means for openingsaid si nalling circuit at the end of a definite timeperiodduringwhichsaidfirstmeansremains continuously restored.

4. In combination with a current distributin circuit, a control relay insaid circuit energised or deenergized according to whether said circuitis energizedor deenergized, a signalling circuit, a second relay forclosing said signalling circuit, a slow-to-release relay and aslow-to-operate relay energizing as a result of deenergization of agiven duration of the control relay for operating said second relay toclose said signalling circuit, a maintaining relay energizing as aresult of the energization of said slow-to-operate relay for maintainingsaid second relay operated independent of said slow-to-release andslow-to-operate relays, and a second slow-to-operate relay operativelyenergizing as a result of the deenergization of said slow-to-operaterelay for a definite length of time following the reenergization of saidcontrol relay for a corresponding length of time for restoring saidsecond relay and said maintaining relay to open said signalling circuit,said slow-to-release and first slow to-operate relays cooperating toprevent the operative energization of said second slow-tooperate relayfollowing a deenergimtion of said control of a duration less than saiddefinite length 0! time.

BINAR- H. HOLT.

